A numerical-physical fusion method for deformation analysis of railway foundation under fault movement

Abstract

The present application relates to the technical field of railway foundation deformation, and discloses a numerical and physical fusion method for railway foundation deformation analysis under fault zone dislocation, comprising: establishing a physical experiment platform, a simulation model, a fault zone space dislocation deformation statistical model, and obtaining boundary conditions; loading the boundary conditions on the physical experiment platform and the simulation model to obtain the spatial deformation of the tunnel structure; comparing the spatial deformation of the tunnel structure under the physical experiment conditions and the simulation conditions, and outputting the tunnel inverted arch displacement curve along the fault dislocation direction after meeting the conditions. The present application effectively combines the active fault zone-tunnel structure physical experiment platform and the simulation model, and guides and corrects the simulation model parameters through the physical experiment results, accurately analyzes the deformation evolution and the space-time law of the fault zone-tunnel structure system, has rich simulative working condition types, meets the pre-research needs of railway construction in the western fault zone multiple occurrence area, and has high accuracy and robustness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of railway foundation deformation, in particular to a numerical-physical fusion method for railway foundation deformation analysis under fault zone dislocation. BACKGROUND

[0002] The plate-type ballastless track structure commonly used in high-speed railways has large rigidity, and if it cannot have good coordination with the deformation of the underlying foundation, the overall geometric behavior of the line will deteriorate, even large-area damage and voiding will occur, the maintenance and repair cost of the railway infrastructure will increase, and even the running safety of high-speed trains will be affected.

[0003] The difficulties in the research on the space-time law of active fault zone-underlying tunnel foundation deformation are as follows: 1) Most of the current experiments consider fewer objective factors, mostly aiming at a single fault dip angle (45°, 60°, 75°) and a single active fault zone type (normal fault, reverse fault, strike-slip fault), and lack a systematic experimental platform; 2) It is difficult to consider the simultaneous existence of complex stress and active fault, and the acceleration excitation of multiple degrees of freedom cannot be simulated at the boundary; 3) Complex active faults include strike-slip, normal fault, reverse fault, and combined fault, and most platforms cannot simulate complex faults; 4) Most simulation results lack engineering practicality.

[0004] In summary, there is an urgent need for a method for railway foundation deformation analysis under fault zone dislocation with high reliability and strong engineering practical significance to solve the problems in the prior art. SUMMARY

[0005] The present application aims to provide a numerical-physical fusion method for railway foundation deformation analysis under fault zone dislocation with high reliability and strong engineering practical significance, and the specific technical solutions are as follows:

[0006] A numerical-physical fusion method for railway foundation deformation analysis under fault zone dislocation, comprising the following steps:

[0007] Step 1, establish an active fault zone-tunnel structure physical experiment platform; establish a simulation model; establish a fault zone space dislocation deformation statistical model and obtain physical experiment boundary conditions and simulation boundary conditions;

[0008] Step 2, load the physical experiment boundary conditions on the active fault zone-tunnel structure physical experiment platform to obtain the spatial deformation of the tunnel structure under the physical experiment conditions; load the simulation boundary conditions on the simulation model to obtain the spatial deformation of the tunnel structure under the simulation conditions; the spatial deformation of the tunnel structure includes vertical deformation and transverse deformation of the longitudinal distribution of inverted arches;

[0009] Step three, comparing the spatial deformation of the tunnel structure under physical experimental conditions with the spatial deformation of the tunnel structure under simulation conditions, and outputting the tunnel invert displacement curve along the fault displacement direction when the conditions are met.

[0010] Preferably, in step three: taking the center position of the intersection of the fault and the line as the 0 point, the tunnel invert displacement curve along the fault displacement direction includes:

[0011] For normal faults or reverse faults, the vertical deformation curve of the tunnel invert is calculated using the following formula:

[0012] ;

[0013] Wherein: is the vertical deformation of the tunnel invert; is the longitudinal coordinate value of the tunnel; is the displacement deformation of the normal fault or reverse fault; is the width of the fault; is the diameter of the tunnel;

[0014] For strike-slip faults, the lateral deformation curve of the tunnel invert is calculated using the following formula:

[0015] ;

[0016] Wherein: is the lateral deformation of the tunnel invert; is the displacement deformation of the strike-slip fault.

[0017] Preferably, the step two specifically includes:

[0018] Step 2.1, measuring material parameters, including:

[0019] For rock-soil mass, triaxial shear test is used: the soil sample is placed in the triaxial shear tester, the confining pressure and axial stress are applied, then the shear is performed, and the axial stress σ and shear displacement are recorded; the internal friction angle and the cohesion c are calculated according to the curve and formula ;

[0020] For concrete and rock-soil mass materials, uniaxial tensile test or compression test is performed: ; wherein: E is the elastic modulus of the material; and σ is the strain and stress of the material under tension or compression;

[0021] For Poisson's ratio, it is determined by the ratio of lateral strain to axial strain : ;

[0022] Step 2.2, based on the material parameters tested in step 2.1, the physical parameters in the real situation are calculated using the scale ratio as the parameters of the simulation model;

[0023] Step 2.3, the physical experiment boundary conditions are applied in sections, and when a section is loaded, the spatial deformation of the tunnel structure under the physical experiment boundary conditions is saved in real time, denoted as ;

[0024] Step 2.4, the spatial deformation of the tunnel structure under the current boundary conditions is calculated using the simulation model, and the spatial deformation of the tunnel structure under the simulation conditions is saved in real time, denoted as .

[0025] Preferably, in the third step: the spatial deformation of the tunnel structure under the physical experiment conditions and the spatial deformation of the tunnel structure under the simulation conditions are compared, which is specifically:

[0026] Error is calculated by the following formula:

[0027] ;

[0028] In the formula: is the displacement scale ratio;

[0029] When is satisfied, it is considered to meet the conditions; is the convergence condition; otherwise, the Newton-Raphson iterative method is used to calculate by perturbing a parameter variable of the material elastic modulus , if , the material elastic modulus is updated to ; if , the material elastic modulus is updated to .

[0030] Preferably, the active fracture zone-tunnel structure physical experiment platform specifically includes:

[0031] Build a loading device that meets the boundary conditions required for fault dislocation; the loading device includes a hydraulic oil pump, a jack, a detachable steel block, and a sensor;

[0032] According to the tunnel structure design drawings, a scale experiment model is established with a scale of 1:30~1:60;

[0033] According to the scale ratio, the amount of rock-soil, rubber, gypsum, and PVC plate materials required for the experiment is calculated to make a tunnel model;

[0034] A tunnel model is installed inside the physical experiment model box, and the required displacement gauges and strain gauges are installed around the tunnel model. Surrounding rock is set up around the tunnel model by burying. When setting up the surrounding rock, prefabricated fault fracture zone material is installed and an adhesive material is applied to simulate the creep of the hanging wall and footwall of the fault. The physical experiment model box has a fixed boundary at the end, free boundaries on both sides, and displacement boundaries are applied at the bottom using jacks.

[0035] Preferably, the simulation model is established by: based on the tunnel structure design drawings, using finite element method, finite difference method or discrete element method analysis software to establish a 1:1 simulation model; the simulation model is a numerical model of tunnel-surrounding rock-fault interaction, and the Mohr-Coulomb model and CDP model are introduced respectively to characterize the damage characteristics of the soil and concrete.

[0036] Preferably, establishing a statistical model of spatial displacement deformation of the fault zone and obtaining physical experimental boundary conditions and simulation boundary conditions specifically includes:

[0037] Real-time monitoring of the deformation of the fault zone along a railway line was conducted to obtain the fault zone type, vertical creep deformation, and lateral creep deformation at different locations. Engineering geological data and relevant literature near the foundation structure of railway tunnels laid in existing fault zones were investigated, and the fault zone deformation data recorded in the data were classified.

[0038] The spatial deformation of the fracture zone after statistical analysis is fitted. The representative value of the deformation in each time unit is obtained by statistical analysis using a fixed time unit. The distribution type of the representative value is calculated and fitted. The distribution types include extreme value type I and extreme value type II.

[0039] The sampling method in statistical analysis is used to extract the deformation value of the fracture zone with a 95% confidence level from the statistical model; the inversion is performed according to the experimental conditions, and the simulated data is used as the boundary conditions of the physical experiment and the simulation.

[0040] Preferably, the simulated data includes the annual vertical and strike-slip displacement of the fault zone.

[0041] The technical scheme of the present application has the following beneficial effects: the present application first establishes an active fault zone-tunnel structure physical experiment platform, establishes a simulation model, establishes a fault zone spatial dislocation deformation statistical model and obtains physical experiment boundary conditions and simulation boundary conditions, then loads the physical experiment boundary conditions on the active fault zone-tunnel structure physical experiment platform to obtain the spatial deformation of the tunnel structure under the physical experiment conditions, loads the simulation boundary conditions on the simulation model to obtain the spatial deformation of the tunnel structure under the simulation conditions, the spatial deformation of the tunnel structure includes vertical deformation and transverse deformation of the inverted arch along the longitudinal direction, finally, the spatial deformation of the tunnel structure under the physical experiment conditions and the spatial deformation of the tunnel structure under the simulation conditions are compared, and the tunnel inverted arch displacement curve along the fault dislocation direction is output when the conditions are met. The active fault zone-tunnel structure physical experiment platform and the simulation model are effectively combined, and the physical experiment results are used to guide and correct the simulation model parameters, and the tunnel inverted arch displacement curve along the fault dislocation direction is output when the conditions are met, the deformation evolution and the space-time law of the fault zone-tunnel structure system are accurately analyzed, the work condition types that can be simulated are rich, the pre-research needs of railway construction in the western fault zone multiple occurrence area are met, and the present application has high accuracy and robustness.

[0042] In addition to the objects, features and advantages described above, the present application has other objects, features and advantages. The present application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0043] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate the preferred embodiments of the application and assist in the explanation of the application. In the drawings, the same reference numbers represent the same elements throughout the several views of the drawings:

[0044] Figure 1 is a flow chart of the numerical and physical fusion method for railway foundation deformation analysis under fault dislocation in the present application;

[0045] Figure 2 is a schematic diagram of the measurement point arrangement of the displacement and strain sensors arranged on the reduced-scale tunnel test piece in the present application;

[0046] Figure 3 is a schematic diagram of the overall structure of the physical experiment platform and the platform loading mode in the present application, wherein: (a) is an end view of the platform; (b) is a side view of the platform; (c) is a schematic diagram of the normal and reverse fault simulation loading mode; (d) is a schematic diagram of the strike-slip fault simulation loading mode;

[0047] Figure 4 is a schematic diagram of the active fault zone-tunnel foundation deformation space-time law simulation analysis model in the present application;

[0048] Figure 5Is the statistical model of spatial dislocation deformation of the fracture zone in the application, wherein: (a) is the vertical annual dislocation amount; (b) is the strike-slip annual dislocation amount;

[0049] Figure 6 Is the vertical deformation of the tunnel invert longitudinal distribution in the application, wherein: (a) is the vertical deformation of the tunnel invert longitudinal distribution after the first iteration; (b) is the vertical deformation of the tunnel invert longitudinal distribution after the second iteration; (c) is the vertical deformation of the tunnel invert longitudinal distribution after the third iteration;

[0050] Figure 7 Is the horizontal deformation of the tunnel invert longitudinal distribution in the application, wherein: (a) is the horizontal deformation of the tunnel invert longitudinal distribution after the first iteration; (b) is the horizontal deformation of the tunnel invert longitudinal distribution after the second iteration; (c) is the horizontal deformation of the tunnel invert longitudinal distribution after the third iteration;

[0051] Figure 8 Is the spatial distribution and evolution rule of the tunnel structure deformation in the application, wherein: (a) is the vertical deformation of the tunnel invert under the normal fault; (b) is the vertical deformation of the tunnel invert under the reverse fault; (c) is the horizontal deformation of the tunnel invert under the strike-slip fault. DETAILED DESCRIPTION

[0052] The embodiments of the application are described in detail below with reference to the accompanying drawings, but the application can be implemented in various different ways within the scope defined and covered by the claims.

[0053] Embodiment:

[0054] Reference Figure 1 A numerical-physical fusion method for railway foundation deformation analysis under the dislocation of the fracture zone, comprising the following steps:

[0055] Step one, establish an active fracture zone-tunnel structure physical experiment platform; establish a simulation model; establish a statistical model of spatial dislocation deformation of the fracture zone and obtain the physical experiment boundary conditions and the simulation boundary conditions;

[0056] Step two, load the physical experiment boundary conditions to the active fracture zone-tunnel structure physical experiment platform, and obtain the spatial deformation of the tunnel structure under the physical experiment conditions; load the simulation boundary conditions to the simulation model, and obtain the spatial deformation of the tunnel structure under the simulation conditions; the spatial deformation of the tunnel structure includes the vertical deformation and the horizontal deformation of the tunnel invert longitudinal distribution;

[0057] Step three, compare the spatial deformation of the tunnel structure under the physical experiment conditions and the spatial deformation of the tunnel structure under the simulation conditions, and output the displacement curve of the tunnel invert along the fault dislocation direction after meeting the conditions.

[0058] The preferred embodiment of the establishment of active fault zone-tunnel structure physical experiment platform includes the following steps:

[0059] Step A, build a loading device that meets the boundary conditions required for fault zone dislocation, mainly composed of hydraulic oil pump, jack, detachable steel block, sensor; detachable steel block is mainly used to simulate different dislocation angles of fault zone; the loading platform can realize the simulation of three-dimensional confining pressure and acceleration boundary;

[0060] Step B, according to the construction site drawings or reference to the existing active fault zone on the design drawings of the tunnel structure, 1:60 scale experiment model is established; due to the deformation of the fault zone itself is greatly influenced by geological structure, geological movement and environmental factors, the experiment of the deformation law of the fault zone itself has strong randomness, so the experimental conditions and results are difficult to reproduce, and may not be applicable to the deformation-failure mechanism of tunnel-surrounding rock structure under fault dislocation. The experiment can mainly summarize the actual geological conditions provided by the design data: (I) different fault zone dip angles; (II) normal / reverse fault; (III) different surrounding rock grades; (IV) tunnel-fault zone penetration angle; (V) deformation law of reserved amount, segmented tunnel.

[0061] Step C, calculate the amount of rock-soil, rubber, gypsum and PVC plate materials required for the experiment according to the scale ratio;

[0062] The specific scale ratio of each physical parameter is shown in the following table:

[0063] Table 1 Specific scale ratio of each physical parameter

[0064]

[0065] The specific materials used in the experiment are as follows:

[0066] a. Experiment surrounding rock material: use fly ash, river sand and machine oil to configure similar materials of different surrounding rock grades; b. Scale tunnel specimen: use gypsum, water and barite to configure lining similar materials; c. Fault zone filling material: two layers of PVC plate smeared with butter in the middle.

[0067] Step D, purchase a physical experiment model box, precast tunnel gypsum model and install displacement meters and strain gauges required around the tunnel, and use backfilling method to fill the tunnel surrounding rock materials;

[0068] For displacement and strain sensors in the experiment, the measurement point arrangement is as follows Figure 2As shown in the figure, wherein: CD1-CD8 are the numbers of measuring points installed on the tunnel wall, wherein: CD1 is located at the top of the tunnel segment, CD2 and CD8 are located at the connection between the upper step and the middle step on both sides, CD3 and CD7 are located at the connection between the middle step and the lower step on both sides, CD4 and CD6 are located at the connection between the lower step and the inverted arch on both sides, and CD5 is located at the bottom of the inverted arch.

[0069] Step E, install the prefabricated fault fracture zone material and smear the adhesive material for simulating the creep of the hanging wall and the foot wall of the fault when filling the surrounding rock;

[0070] Step F, apply the model constraint condition, specifically, fixed hinge is applied at both ends of the experimental box tunnel portal. The overall structure of the physical experiment platform and the platform loading mode are as shown in Figure 3 As shown in the figure, a steel block with an inclination angle of 60° is used to simulate the dislocation of the fracture zone, wherein: (a) and (b) are the front view and side view of the test platform, (c) is a schematic diagram of the bottom jacking simulation of normal-thrust fault, and (d) is a schematic diagram of the side jacking simulation of sliding fault, which can be used to simulate the jacking of the hanging wall of normal fault and lateral dislocation, to simulate the boundary conditions of normal-thrust fault and strike-slip fault, and the boundary conditions at both ends of the experimental box are fixed constraints.

[0071] Preferably, the simulation model comprises the following steps:

[0072] A simulation model with the same working condition as the model experiment is established by using a commercial finite element software. The model size is 100m (width) x 100m (height), the inclination angle is 60°, and the overburden thickness is 45m. The soil constitutive model complies with the Mohr-Coulomb yield criterion, and the CDP model is selected to represent the material damage characteristics under large deformation. The mechanical parameters of the soil, the fracture zone and the tunnel lining are shown in Table 2. The soil and the tunnel are set as "face-face contact", the tangent is "penalty" friction, and the friction coefficient is 0.3, and the normal is "hard" contact. The main parameters of the simulation model are determined according to the physical test and the scale ratio, see Table 2. The schematic diagram of the simulation analysis model of the active fracture zone-tunnel foundation deformation space-time law is as shown in Figure 4 As shown in the figure, The tunnel segment diameter is D, The dislocation angle of the fracture zone is a, L S The longitudinal length of the tunnel model is L, L R The longitudinal length of the fracture zone is L).

[0073] Table 2 Mechanical parameters of soil, fracture zone and tunnel lining

[0074]

[0075] In the preferred embodiment of the present application, the statistical model of spatial dislocation deformation of the fracture zone is established, and the physical experiment boundary conditions and the simulation boundary conditions are obtained as follows: Taking the deformation of the Jiali fracture zone in the past three years as an example, a preliminary statistical model of the deformation of the fracture zone is established. The measured data on site are shown in Table 3.

[0076] Table 3 Measured data on site

[0077]

[0078] Taking the annual deformation of the fracture zone as a basic parameter, the statistical model of spatial dislocation deformation of the fracture zone is established, as shown in FIG. a of Figure 5 According to the statistical results, it can be considered that the annual deformation of the Jiali fracture zone conforms to the normal distribution rule. The normal distribution function is used to fit the vertical and strike-slip dislocation deformation of the fracture zone, and the following results are obtained: the average value of the vertical annual dislocation of the fracture zone is 20.7078 mm, and the standard deviation is 1.38 mm; the average value of the strike-slip annual dislocation of the fracture zone is 2.5265 mm, and the standard deviation is 0.32141 mm.

[0079] The Monte-Carlo method used in traditional statistical analysis is used for random sampling in the statistical model, and the sampling results meet the 95% confidence level. As shown in FIG. b of Figure 5 , the random sampling points are uniformly distributed around the mean value, which indicates that the random sample can well represent the basic probability characteristics of the statistical model. According to the “3 ” principle in probability theory, combined with the average value and standard deviation of the annual deformation obtained above, it can be preliminarily estimated that the annual deformation range of the Jiali fracture zone is [16.56, 24.85] mm in the vertical direction and [1.56, 3.49] mm in the strike-slip direction. The established statistical model of the fracture zone can generate the annual dislocation samples of the vertical and strike-slip of the fracture zone and can be used as the boundary conditions of the numerical model.

[0080] In the preferred embodiment of the present application, the physical experiment boundary conditions are loaded on the active fracture zone-tunnel structure physical experiment platform to obtain the spatial deformation of the tunnel structure under the physical experiment conditions, and the simulation boundary conditions are loaded on the simulation model to obtain the spatial deformation of the tunnel structure under the simulation conditions, which specifically includes:

[0081] The physical experiment boundary conditions are loaded, and the specific implementation is to use the hydraulic oil pump to apply a pushing force to the bottom or the right end boundary of the lower plate, as shown in FIGS. a and b of Figure 3 . According to the comparison between the pushing amount recorded by the jack and the applied deformation amount, the model loading is stopped when the current deformation amount is reached. The upward, downward and lateral loading can be used to simulate the boundary conditions of the reverse fault, normal fault and strike-slip fault.

[0082] The simulation model parameters are corrected by using the physical test results, which specifically includes the following steps:

[0083] (1) Test the basic physical parameters of the experimental material, and calculate the physical parameters in the real situation by using the scale ratio, which are used as the parameters of the simulation model, as shown in Table 4:

[0084] Table 4 Table of physical parameters in the real situation and used as the parameters of the simulation model

[0085]

[0086] (2) Apply the boundary conditions in sections, and record the physical experimental results after loading a section: the spatial deformation of the tunnel structure; save the spatial deformation of the tunnel structure under the current boundary conditions obtained in B in real time through the cloud PC, and mark it as .

[0087] (3) Calculate the spatial deformation of the tunnel structure under the current boundary conditions by using the simulation model, that is, the vertical and lateral deformation of the tunnel invert along the longitudinal direction, as shown in Figs. Figure 6 (a) and 7(a).

[0088] In this embodiment, the spatial deformation of the tunnel structure under the physical experimental conditions and the spatial deformation of the tunnel structure under the simulation conditions are compared, and the displacement curve of the tunnel invert along the fault displacement direction is output after meeting the conditions, as follows:

[0089] The saved spatial deformation of the tunnel structure is compared with the spatial deformation of the tunnel structure in the simulation . If there is an error, it can be represented as , wherein: is the displacement scale ratio;

[0090] A preset iteration convergence criterion (i.e., error tolerance ) is used to update the elastic modulus in the numerical model by iterating the simulation calculation results and the experimental results until the model meets the convergence condition. Specifically, if the second norm of exceeds the preset error tolerance (taking the value 1e-7 in this embodiment), the physical parameters of the current model need to be updated by iteration; the iteration method is specifically to use the Newton-Raphson iteration method to regard the simulation model as a nonlinear system, calculate the residual error between the current result and the physical experimental result after modifying the parameters, and update the simulation model parameters by continuous iteration, so that the residual error between the current simulation result and the physical experimental result is less than the convergence condition (i.e., the error tolerance ), it can be considered that the current simulation model can represent the specific working condition simulated by the current physical experiment. By setting a parameter variable disturbance of the material elastic modulus , the calculation result of the calculation model after the parameter disturbance is calculated, i.e. the parameter updates the numerical model and calculates the structural response ( j represent the results after the first j iteration), and the experimental results are taken as the true values to iterate the model. After n iterations, the disturbance is obtained as the final updated parameter value of the current model . The iteration formula can be calculated according to the following formula:

[0091] ;

[0092] Among them: is the stiffness matrix at the j th iteration step, and the elastic modulus is ; is the equivalent load column array of the current boundary condition; is the tangent stiffness matrix at the j th iteration step; and are the elastic modulus and its disturbance, respectively; is the displacement scale ratio; is the displacement after the j th iteration step.

[0093] If the calculated >0, the disturbance can be reduced (i.e. take ), otherwise it is increased (i.e. take ), until after iteration < , , the iteration is ended, and the following iteration formula can be referred to:

[0094] ;

[0095] Among them, is the norm of ; , , represent the first, second, …, elements in the vector .

[0096] In this case, the preset elastic model disturbance =2GPa, and after 2 iterations, the final deformation amount is obtained asFigure 6 (b) and (c) and Figure 7 (b) and (c) are shown.

[0097] The physical experiment boundary condition loading is repeated and the simulation model parameters are corrected using the physical test results to realize multi-scale analysis of the active fault zone-railway tunnel foundation space deformation distribution and evolution mechanism based on the number of material fusion.

[0098] The physical experiment boundary condition loading is repeated and the simulation model parameters are corrected using the physical test results to realize multi-scale analysis of the active fault zone-railway tunnel foundation space deformation distribution and evolution mechanism based on the number of material fusion.

[0099] According to the results of the first iteration, the current model calculation parameters are saved;

[0100] According to Figure 5 The fault zone deformation sampling data in (a) and (b) are used to continue the physical experiment boundary condition loading, i.e. the current boundary conditions are applied to the physical experiment model;

[0101] The simulation model parameters are corrected using the physical test results, i.e. the unknown parameters in the simulation model representing the results of the current experiment are calculated again, the model parameters are corrected again through the iteration of the simulation model, and the tunnel structure deformation space distribution and evolution law under the fault zone deformation condition are obtained, as shown in Figure 8 (a) is the vertical deformation of the tunnel invert under the normal fault; (b) is the vertical deformation of the tunnel invert under the reverse fault; (c) is the horizontal deformation of the tunnel invert under the strike-slip fault. Taking the boundary conditions of 50mm, 100mm, 150mm, 200mm for normal faults and reverse faults and 20mm, 40mm, 60mm, 80mm for strike-slip faults as examples, the tunnel structure deformation curve under the fault displacement condition can be obtained by using the curve interpolation fitting method according to the loading of different boundary conditions. According to the calculation results, the displacement curve of the tunnel invert along the fault displacement direction under the three types of fault displacement is "S" type, which can be summarized as follows:

[0102] (1) Taking the intersection center position of the fault and the line as 0 point, for normal faults or reverse faults, the vertical deformation curve of the tunnel invert is calculated by the following formula:

[0103] ;

[0104] In the formula: is the vertical deformation of the tunnel invert (mm); is the longitudinal coordinate value of the tunnel (m); is the displacement deformation of the normal / reverse fault (mm), wherein the displacement of the reverse fault is negative and the displacement of the normal fault is positive; is the width of the fault (m); is the diameter of the tunnel (m);

[0105] (2) Taking the intersection center position of the fault and the line as 0 point, for the strike-slip fault, the transverse deformation curve of the tunnel inverted arch is calculated by using the following formula:

[0106] ;

[0107] In the formula: is the transverse deformation of the tunnel inverted arch (mm); is the longitudinal coordinate value of the tunnel (m); is the dislocation deformation of the strike-slip fault along the longitudinal direction (mm); is the width of the fault (m); is the diameter of the tunnel (m).

[0108] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A data-physical fusion method for analyzing railway foundation deformation under fault zone slippage, characterized in that, Includes the following steps: Step 1: Establish a physical experimental platform for the active fault zone-tunnel structure; establish a simulation model; establish a statistical model of spatial displacement deformation of the fault zone and obtain the physical experimental boundary conditions and simulation boundary conditions; Step 2: Apply physical experimental boundary conditions to the active fault zone-tunnel structure physical experimental platform to obtain the spatial deformation of the tunnel structure under physical experimental conditions; apply simulation boundary conditions to the simulation model to obtain the spatial deformation of the tunnel structure under simulation conditions; the spatial deformation of the tunnel structure includes the vertical deformation and lateral deformation of the invert arch distributed longitudinally. Step 3: Compare the spatial deformation of the tunnel structure under physical experimental conditions with the spatial deformation of the tunnel structure under simulation conditions. Once the conditions are met, output the displacement curve of the tunnel invert arch along the fault displacement direction. Step two specifically includes: Step 2.1: Measure material parameters, including: For soil and rock masses, triaxial shear tests are used to obtain parameters. Specifically, the soil sample is placed in a triaxial apparatus, confining pressure and axial stress are applied, and then sheared. The axial stress σ and shear displacement are recorded. ;according to Curves and Formulas Calculate the internal friction angle and cohesion c; For concrete and soil materials, uniaxial tensile or compression tests are performed: Where: E is the elastic modulus of the material; σ represents the strain and stress of the material under tension or compression; For Poisson's ratio, it is obtained through transverse strain. and axial strain The ratio is determined as follows: ; Step 2.2: Based on the material parameters obtained in Step 2.1, calculate the physical parameters under real conditions using the scaling factor and use them as parameters for the simulation model; Step 2.3: Apply the physical experiment boundary conditions in segments. After each segment is loaded, save the spatial deformation of the tunnel structure under the physical experiment boundary conditions in real time, denoted as... ; Step 2.4: Calculate the spatial deformation of the tunnel structure under the current boundary conditions using a simulation model, and save the spatial deformation of the tunnel structure under the simulation conditions in real time, denoted as... ; In step three, comparing the spatial deformation of the tunnel structure under physical experimental conditions with the spatial deformation of the tunnel structure under simulation conditions specifically involves: error Calculate using the following formula: ； in: This is the displacement scaling ratio; satisfy When, it is considered that the condition is met, where: The convergence condition is set; otherwise, the Newton-Raphson iterative method is used by pre-setting a perturbation of a parameter variable on the material's elastic modulus. Perform iterative calculations and make a judgment: If satisfied Then the updated material elastic modulus is: ; If satisfied Then the updated material elastic modulus is: .

2. The data-physical fusion method for railway foundation deformation analysis under fault zone slippage according to claim 1, characterized in that, In step three: taking the center of the intersection of the fault and the railway line as point 0, the displacement curve of the tunnel invert along the fault slip direction includes: For normal or reverse faults, the vertical deformation curve of the tunnel invert is calculated using the following formula: ； in: This represents the vertical deformation of the tunnel invert arch. These are the longitudinal coordinates of the tunnel; This refers to the displacement deformation of a normal or reverse fault. The width of the fault; The diameter of the tunnel; For strike-slip faults, the lateral deformation curve of the tunnel invert is calculated using the following formula: ； in: This refers to the lateral deformation of the tunnel invert arch. This represents the displacement deformation of the strike-slip fault.

3. The data-physical fusion method for railway foundation deformation analysis under fault zone slippage according to claim 1 or 2, characterized in that, The establishment of an experimental physical platform for active fault zones and tunnel structures specifically includes: Construct a loading device that meets the boundary conditions required for fault zone displacement; the loading device includes a hydraulic pump, jacks, detachable steel blocks, and sensors; Based on the tunnel structure design drawings, a scaled-down experimental model was established at a scale of 1:30 to 1:

60. Based on the scale, calculate the required quantities of soil, rubber, plaster, and PVC board materials for the experiment and construct a tunnel model. A tunnel model is installed inside the physical experiment model box, and the required displacement gauges and strain gauges are installed around the tunnel model. Surrounding rock is set up around the tunnel model by burying. When setting up the surrounding rock, prefabricated fault fracture zone material is installed and an adhesive material is applied to simulate the creep of the hanging wall and footwall of the fault. The physical experiment model box has a fixed boundary at the end, free boundaries on both sides, and displacement boundaries are applied at the bottom using jacks.

4. The data-physical fusion method for railway foundation deformation analysis under fault zone slippage according to claim 1, characterized in that, The specific steps for establishing the simulation model are as follows: Based on the tunnel structure design drawings, a 1:1 simulation model is established using finite element method, finite difference method, or discrete element method analysis software; the simulation model is a numerical model of the interaction between the tunnel, surrounding rock, and fault, and the Mohr-Coulomb model and CDP model are introduced respectively to characterize the damage characteristics of the soil and concrete.

5. The data-physical fusion method for railway foundation deformation analysis under fault zone slippage according to claim 4, characterized in that, Establishing a statistical model of spatial displacement deformation of the fault zone and obtaining physical experimental boundary conditions and simulation boundary conditions specifically includes: Real-time monitoring of the deformation of fault zones along a railway line was conducted to obtain the fault zone type, vertical creep deformation, and lateral creep deformation at different locations; engineering geological data near the foundation structure of railway tunnels laid in existing fault zones were investigated, and the fault zone deformation data recorded in the data were classified. The spatial deformation of the fracture zone after statistical analysis is fitted. The representative value of the deformation in each time unit is obtained by statistical analysis using a fixed time unit. The distribution type of the representative value is calculated and fitted. The distribution types include extreme value type I and extreme value type II. The sampling method in statistical analysis is used to extract the deformation value of the fracture zone with a 95% confidence level from the statistical model; the inversion is performed according to the experimental conditions, and the simulated data is used as the boundary conditions of the physical experiment and the simulation.

6. The data-physical fusion method for railway foundation deformation analysis under fault zone slippage according to claim 5, characterized in that, The simulated data includes the annual vertical and strike-slip displacement of the fault zone.

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